I 



W. J. Taylor on Rock Guano. 177 



attendant in sickness and companion in his solitude. They 

 lived most happily together, and at his death, he left her a com- 

 fortable provision for the remainder of her life. Mr. itichaux 

 was in easy circumstances, but by no means rich. To his title 

 of Chevalier de la Legion d'Honneur, he added, those of Cor- 

 respondent of the French Institute, of Member of the American 

 Philosophical Societj?-, of the Central Society of Agriculture of 

 Paris, of the Society of Agriculture and Arts of Boston, &c,, &c. 



Art. XIV. — Investigation on the Roch Guano from the Mands of 



the Caribbean Sea ; by Wm. J. Taylor.* 



Though much has been written and published on the Colum- 

 bian guano of the Caribbean Sea, (which is also termed phos- 

 phatic guano, native super-phosphate of lime, &c.,) I have con- 

 sidered the subject not entirely exhausted, and for some time 

 past have been paying especial attention to its composition, be- 

 sides endeavoring to gather all possible information regarding 

 its mode of occurrence. To Dr. I>. Luther, president of the i 



Philadelphia Guano Company, I am particularly indebted for his 

 kindness in furnishing me with material for the investigation 

 from the various groups of islands, and for information regard- 

 ing its occurrence. To Dr. F. A. Gcnth I am also indebted for 

 allowing me to make the investigation in his laboratory. 



The guano rock is found on islands northeast and north of the 

 coast of Venezuela in the Caribbean Sea, and belonging to that 

 republic ; the islands form groups or keys composed of one hund- 

 red or more small islands, inhabited principally, and indeed almost 

 solely, by water fowl, who resort there in immense numbers for 

 laying their eggs. Mr. Cassin informs me that the birds are 

 those commonly known as gulls, pelicans, and cormorants ; these 



I have been the instruments by which the immense deposits of 



guano have been formed. But what the process has been is a 



t problem not yet fully solved 



^ The Columbian guano is a hard rock, consisting of two dis- 

 tinct portions; the outer exterior crust, consisting of a white, 

 and frequently reniform coating, which, in places where it is not 

 decomposed, has a polished surface not unlike enamel ; it is com- 

 posed of concentric layers, each of which is about two or more 

 lines in thickness. The entire outer crust forms but a very 

 small proportion of the whole rock; a carefully selected portion 

 of this has been analyzed, which had not undergone any appar- 

 ent decomposition, and upon which the enamelled surface was 

 Well preserved. In some portions the reniform surface is dis- 



March, 1857, 



Academy 



SECONO SERIES, VOL. XXIV, NO. 71. — SEPT., 1857. 



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